diff --git a/src/platform/posix/include/platform/lib/clk.h b/src/platform/posix/include/platform/lib/clk.h
index 3c9ff3b96950..7d396330a0cb 100644
--- a/src/platform/posix/include/platform/lib/clk.h
+++ b/src/platform/posix/include/platform/lib/clk.h
@@ -5,6 +5,7 @@
 
 #define CLK_MAX_CPU_HZ CONFIG_SYS_CLOCK_HW_CYCLES_PER_SEC
 #define CPU_LPRO_FREQ_IDX 1
+#define CPU_LOWEST_FREQ_IDX CPU_LPRO_FREQ_IDX
 
 /* This is not a platform function, it's defined in src/lib/clk.c.
  * But the declaration has historically been in the platform layer, so